I don't consider either set to be weak or gimping your damage output, unless you're basing that on the lack of procs. If you were to 6-slot Thunderstrike, you would be at +143% for damage (far in excess of the ED max) and would be at +69% for accuracy, endurance and recharge. If you don't need the 6-piece set defense bonus, you can drop the dam/end and still be well over ED max for damage. 6-slotted Artillery provides +101% damage (over ED max), +90% recharge, +69% accuracy, +48% endurance and +26% range. The range enhancement is really useful in the 40-foot cones and would increase, not decrease damage output.